Piston



March 31, 1936. G. M.'BARNES PIsToN Filed Nov. 19, 1934 Ils@ Inventn Bladen-n M .'E'larnes yM/M. @M

Atturne Patented v Mar. 31, 1936 UNITED STATES PATENT OFFICE 2.035,45 -rrs'roN Gladeon M.

Barnes, United States Army, Hastings, Ml

Application November 19, 1934, Serial No. 753.850

1 Claim.

(Cl. ISI-18) The invention decided herein may be manufactured and used by or for the Government for governmental purposes, without thev payment to me of anyroyalty thereon.

This invention relates to a piston and more particularly it has reference to means for providing a seal between the piston and its cylinder.

The purpose of the invention is to provide a piston seal which is not only gas tight but which improves lubrication and thereby prevents wear of the parts. The sealing material is placed under pressure by the pressure medium which acts on the piston or is acted o'n by the piston.

To these and other ends, the invention consists in the construction, arrangement and combination of elements described hereinafter and pointed out in the claim forming a part oi' this specicatio'n. y

Several practical embodiments of the invention are illustrated in the accompanying drawing, wherein:

Fig. 1 is a longitudinal sectional view of a piston and cylinder provided with the improved seal.

Fig. 2 is a similar view of a dilerent application of the invention.

Referring to Fig. 1 there is shown a typical piston comprising a head 5 having spaced packing rings 6 6, a rod 1 connected to the head by a wrist pin 8, and a pipe 9 for conducting lubricant under pressure to a peripheral groove Ill in the wrist pin..

The wrist pin is modiiied by providing radial passages II--II from the groove I0 and an in.

clined passage I2 leading from passages Il to a passage I3 in the head 5. A passage Il leads from the passage I3 td a peripheral groove I5 positioned between the packing rings 8 6.. A ball valve I6 is placed in the passage I3 between the passage I4 and the wrist pin and prevents return of the lubricant after it has been forced past the valve.

The paage I3 is joined to a passage I1 which is in communication with the iront pressure tace or the piston head. A ball valve Il is placed in the passage l1.

The lubricant which is conducted to the space between the packing rings 6-6 is acted on by a high pressure medium admitted through the valved passage I1 and forms a gas-tight seal between the piston head and itsv cylinder. As the pressure medium is trapped, the lubricant remains under pressure a considerable length of time, and in the case of a gas engine an effective seal is maintained during the exhaust, intake and compression strokes of the piston. This pressure is renewed each time an explosion occurs in the cylinder.

In Fig. 2 the invention is illustrated as applied to the packing of a cylinder I9 which moves with respect to a xed rod 20. One end of the cylinder is closed by a head 2| which is retained by a disc l 22 threadedly attached to the cylinder. The head and disc are formed with apertures, respectively 23 and 24, to accommodate the rod 20.

The head 2l carries a pair of spaced packing rings 25--25 which are held against the rod 20 by springs 26. The head is formed with an annular groove 21 between the packing rings and this groove is illled with a heavy grease 28 which is admitted through a passage 29 in the head and a passage 30 in the disc, the latter being associated with a tting 3l secured in the disc. The inner face of the disc is fo ed with an annular groove 32 which is in communication with the passage 30 and is also filled with the grease 28.

The head is provided witha passage 33 leading from its pressure side to theannular groove 21. A pressure medium from the chamber 34 is therefore capable of acting on the grease winch forms an effective seal.

I claim:

A piston including a head, a wrist pin in the head, a rdd connected to the wrist pin, a line for conducting lubricant to the wrist pin, spaced packing rings carried by the head, passages in the wrist pin and head for conducting lubricant to the side face of the head between. the packing rings, a one-way valve in one of said passages, a passage leading from the pressure face of the head to said preceding passage and a one-way valve in said passage.

GLADEON M. BARNES. 

